On the positive note, what is really saving you is the OEM bead itself, and that your are really gluing the sight to mostly (the bulb of the bead).
The down side, the front sight is peen in place (not threaded in), so if at some point that the OEM bead pops out, the new sight is going to go with it.
Truth is, you have any talent and a blast cabinet with Oxide media, then place the sight in place, use a pencil to mark where the sight is going to fit on the barrel surface, tape off and the oxide blast abrade the surface the nickle plating off on the barrel under where the sight is to be mounted so give any epoxy a fighting chance to correctly bond to the barrel metal instead.
Short of that, might want to look for another bead design, hence one that you remove the OEM bead, tap the channel and that the new bead system is threaded on to the barrel instead.